Magnetic Susceptibility of Metal-Insulator System LixZn1-xV2O4

The magnetic susceptibilities of Li x Zn 1- x V 2 O 4 were measured from 80 K to 1100 K. They apparently follow the Curie-Weiss law above and below about 500 K, separately, with different constants. Above about 500 K, they show similar susceptibilities irrespective of their transport properties. Below about 500 K, the Weiss temperatures of metallic oxides are nearly zero. The susceptibility of insulating ZnV 2 O 4 becomes smaller than an extrapolated one, and it suggests a decrease in the effective moment. To explain the conductivity dependent Weiss temperature, a spin orienting interaction by mobile electrons was considered. The decrease of the effective magnetic moment was attributed to the Fermi statistics of quasi-itinerant electrons which extend over a certain range in a periodic lattice.